SW WA Hub Extension Specialist and Knowledge Broker, Dr Mary Anne Glanzlowe, recently attended the second global Sandy Soils Conference, held in Perth. The event brought together experts from across agriculture, mining, and natural resource management to tackle a common challenge: how to better manage sandy soils.
Sandy soils make up around 900 million hectares of arable land globally and cover a large proportion of Western Australia, including most of our cropping regions. Their widespread presence makes them critical to global food production and land use, particularly in dry climates like ours.
Why sandy soils matter in a changing climate
Sandy soils pose several challenges for land managers, including water repellency, poor fertility, soil acidity, poor soil strength, and low water-holding capacity. Of these, two are becoming more urgent as climate conditions shift: soil water repellency and low water-holding capacity.
As rainfall becomes less frequent and temperatures rise, soils that can retain moisture and make water accessible to plant roots become increasingly important for maintaining crop yields. While sandy soils allow for quick infiltration during light rains, they often lose water quickly, making it harder for crops to survive during dry periods.
One proven approach to improve water retention is clay incorporation, which is a form of soil amelioration. Research from the Department of Primary Industries and Regional Development (DPIRD) presented at the conference focused on spreading and mixing clay into sandy topsoil to help retain moisture in the root zone for longer. However, experts caution that this technique must be carefully planned to avoid unintended consequences, such as poor soil structure or nutrient imbalance.
Exploring the science behind water repellency
Another key topic was soil water repellency (also known as non-wetting soil). This is when water fails to penetrate the soil surface, often caused by a hydrophobic coating on soil particles. This condition worsens with high soil temperatures, which are increasingly common in the South-West WA region.
Research presented at the conference showed that while soil type is the main driver of water repellency, climate plays a significant role in how it behaves. Moderate temperatures can help reduce water repellency through increased microbial activity, while very high temperatures may do the opposite. An interesting insight was that while higher soil carbon is good for long-term soil health, it may also increase the risk of water repellency under extreme heat – a trade-off to consider when designing carbon sequestration strategies.
Learning from the field
The conference also included field tours, which Mary-Anne and SW WA Hub Innovation Broker Doug Hamilton Doug Hamilton joined. Attendees visited local grower Trevor Syme’s broadacre cropping property, where he has successfully ameliorated sandy soils using a combination of techniques tailored to his specific challenges, demonstrating how innovation at the farm level can lead to real results.
The tour also explored the challenges of rehabilitation in sand mining sites, viewed engineering trials by the University of Western Australia, and looked at best-practice sandy soil management in horticultural vegetable systems.
As part of the recent Sandy Soils Conference, Stephen Davies (DPIRD), Trevor Syme (Waddi Park Farming), Mary-Anne Glanzlowe (SW WA Hub), Doug Hamilton (SW WA Hub) and Bridget Watkins (South-West WA Regional Soil Coordinator) joined a field trip to Trevor Syme’s farm near Moora. Attendees had the chance to see how Trevor is using soil amelioration techniques to tackle sandy soil constraints and improve crop productivity. The visit also highlighted GRDC-funded trials led by DPIRD, which are testing different approaches to improve soil health and long-term farm resilience.
